Here's an excerpt from the Powerflex manual regarding the / in column 1

An image header line begins with slash character "/c" where c is not a slash or asterisk.
An image end line begins with slash asterisk "/*".
Each image includes all lines of program text up to the next line starting with slash "/". It should be noted that a line starting with double slash "//" would be regarded as a comment if it occurred in the Statement section, but would be the start of a new image in the Image section.

An image may start anywhere in a program, and there may be zero, one or more images in the program. Images may follow immediately after each other, with each image header line ending one image and starting another, or each may end with an image end line.
Immediately after the slash in the image header line is the name of the image, which conforms to the usual rules for an identifier (see later). It is an error if it does not.
The header line may contain the word HELP to signify that this is a help screen (see the HELP statement). For compatibility, the word HELP may appear anywhere on the line, in upper or lower case, even forming part of the image name. The image may not be called HELP, however.
The header line is followed by 0, 1 or more image lines consisting of background text and windows.

The width of the image is limited by the length of a program line (a maximum of 300 characters), but the length of the image is not limited. Portions of images outside the displayable area (generally 24 or 25 lines of 80 columns) are not displayed on the screen but may be printed in reports.

· Example

Here is an example Image Section from a program making use of many of the available options.